A geographic database or a road database may include information about towns, cities, addresses, and the road network that connects the locations. The road network may be defined by road links assigned to geographic locations. Other information about the roads may also be stored such turn restrictions, speed limits, stop sign locations, and traffic signal locations.
Some techniques for collecting information on roads involves manually entering the data into a computer. For example, the existence of turning lanes may be observed by observing videos of traffic. That is, a human technician may watch videos of vehicles traveling roads and marking the observed turn lanes on a map. Alternatively, a human technician may log the turn lanes while collecting map data in a vehicle. That is, during data collection, turn lanes observed in real life are marked on a map. Both of these processes is labor intensive, time consuming, and expensive. Challenges remain in automatic and efficient techniques for automating turn lane identification and coding.